In general, nails for use in construction of residential buildings, and bolts, nuts, rivets, and so forth for use in construction of steel-framed buildings as well as plants are put together on a predetermined weight (number) basis for carrying without any difficulty, and then placed in a cardboard-built box or a resin-made box for sale on the market. In contrast to the resin packing box which has to be stored as it is, viz., in the form of a cubic box, the corrugated cardboard packing box has a board-like shape in a yet-to-be-built condition and therefore occupies less space for storage than does the resin packing box, and is also inexpensive in unit price, with a consequent advantage in convenience.
The types of corrugated cardboard boxes are specified in JIS Z 1507, each of which is assigned a code number and illustrated in a developed view and a cubic view. In the marketplace, the types of corrugated cardboard boxes are popularly known as “A-type”, “B-type”, “C-type”, etc., rather than being referred to as the code numbers defined in JIS. Moreover, corrugated cardboard boxes for packaging articles such as nails are generally put in the category of the A-type (orange carton type). A corrugated cardboard box of this type is formed with lid portions (flaps), each of which covers one-half of the top of the box in an opened state. The lid portion merges with the upper edge of each of two opposed lateral surfaces of the box. The lid portions are bent inwardly in a confronting state from the part of merging so as to close the opened top, and an adhesive tape such as a packing tape or kraft tape is placed at the confronting areas for completion of box building.
In a case where a large quantity of articles, such as nails and bolts, having the same dimension are used at a construction site and so forth, they are directly taken out of a packing box for use at the location of construction work. However, in most cases, a day's work is finished with some of the packed articles left unused. Therefore, in the condition of use as mentioned above, the packing box has to be stored while being left opened. In addition to the A-type, there are known “B-type” and “C-type”. A corrugated cardboard box of the B-type is formed with a single lid, one edge of which merges with one of lateral surfaces of the box, and the other edge opposite the edge at the part of merging is folded over to form a flap for insertion, thereby closing the top of the box in an opened state. The box of this type can be lidded over and over again even after the box is opened. On the other hand, a corrugated cardboard box of the C-type is composed of two separate parts, namely a main body having four lateral surfaces and a bottom surface, and a lid. However, in both of the B-type and the C-type, it is difficult for the lid to be held securely in place so that the box can withstand handling during, e.g. transportation while having heavy articles such as nails packaged therein. Furthermore, there is the possibility that the lid fails to serve the purpose properly after the box is opened due to box deformation caused by heavy articles such as nails housed therein. As another drawback, a corrugated cardboard box of the B-type as well as the C-type has a large opened area and is therefore prone to intrusion of water in the event of sudden rainfall.
Although target articles to be packaged are unknown, in Patent Literature 1, there is disclosed a technology related to a corrugated cardboard box characterized in that it can be sealed over and over again even after opening and that the opened area of the box in an opened state is smaller than the area of the top of the box. In the corrugated cardboard box disclosed in Patent Literature 1, lid portions (outer flaps) that merge with two opposed edges on the top of the box, respectively, overlap each other at their ends on the top, thereby rendering possible re-sealing of the box. An opening for taking out box content is provided in the form of a gap between inner flaps lying inside the lid portions.